Introduction to OracleIntroduction to Oracle

Oracle HistoryOracle History

• 1979 Oracle Release 2

• 1986 client/server relational database

• 1989 Oracle 6

• 1997 Oracle 8 (object relational)

• 1999 Oracle 8i (Java Virtual Machine)

• 2000 Oracle Application Server

• 2001 Oracle 9i database server

• 1979 Oracle Release 2

• 1986 client/server relational database

• 1989 Oracle 6

• 1997 Oracle 8 (object relational)

• 1999 Oracle 8i (Java Virtual Machine)

• 2000 Oracle Application Server

• 2001 Oracle 9i database server

Oracle FamilyOracle Family

• Personal Oracle- for single users. Used to develop systems

• Oracle Standard Edition- (Entry level Workgroup server)

• Oracle Enterprise edition- Extended functionality

• Oracle Lite- (Oracle mobile) single users using wireless devices.

• Personal Oracle- for single users. Used to develop systems

• Oracle Standard Edition- (Entry level Workgroup server)

• Oracle Enterprise edition- Extended functionality

• Oracle Lite- (Oracle mobile) single users using wireless devices.

Some Developer ToolsSome Developer Tools

• Oracle Forms Developer

• Oracle Reports Developer

• Oracle Jdeveloper

• Oracle Designer

• Oracle Forms Developer

• Oracle Reports Developer

• Oracle Jdeveloper

• Oracle Designer

File ProcessingFile Processing

DatabaseProcessing

Database StructureDatabase Structure

• Logical structure - maps the data to the Physical structure.

• Physical structure -part of the operating system’s file structure.

• Memory structure - where all the processing takes place.

• Logical structure - maps the data to the Physical structure.

• Physical structure -part of the operating system’s file structure.

• Memory structure - where all the processing takes place.

The Logical structuresThe Logical structures

• control how the data must be stored in the database.

• five Logical structures:– tablespaces – segments – extents – data blocks– schema objects

• control how the data must be stored in the database.

• five Logical structures:– tablespaces – segments – extents – data blocks– schema objects

Physical structuresPhysical structures

• Parameter files

• Password files

• Datafiles

• Redo log files

• Control files

• Parameter files

• Password files

• Datafiles

• Redo log files

• Control files

Memory structuresMemory structures

• System Global Area (SGA)

• Program Global Area (PGA)

• The Oracle database uses these memory areas to store information before they are made permanent in the database.

• System Global Area (SGA)

• Program Global Area (PGA)

• The Oracle database uses these memory areas to store information before they are made permanent in the database.

TableSpacesTableSpaces

• A database is divided into logical storage units called Tablespaces.

• logical construct for arranging different types of data

• An Oracle database must have at least a system tablespace.

• It is recommended to have different tablespaces for user and system data.

• A database is divided into logical storage units called Tablespaces.

• logical construct for arranging different types of data

• An Oracle database must have at least a system tablespace.

• It is recommended to have different tablespaces for user and system data.

TablespacesTablespaces

• a logical structure• a logical structure

Data1 Data2

Data1_01.dbf Data2_01.dbf Data2_02.dbf

The DATA1Tablespace =One datafile

The DATA2Tablespace =Two datafiles

Create TablespaceCreate Tablespace

CREATE TABLESPACE testDATAFILE '\oraserv\ORADATA\a.dbf'SIZE 10MAUTOEXTEND ON NEXT 10M MAXSIZE 100M;

CREATE TABLE cust(id int,name varchar2(20))TABLESPACE test;

CREATE TABLESPACE testDATAFILE '\oraserv\ORADATA\a.dbf'SIZE 10MAUTOEXTEND ON NEXT 10M MAXSIZE 100M;

CREATE TABLE cust(id int,name varchar2(20))TABLESPACE test;

7 Logical Tablespaces7 Logical Tablespaces

• SYSTEM

• DATA

• INDEX

• USERS

• ROLLBACK

• TEMP

• TOOLS

• SYSTEM

• DATA

• INDEX

• USERS

• ROLLBACK

• TEMP

• TOOLS

Schemas and Schema ObjectsSchemas and Schema Objects

• Collection of database objects– Tables– Views– Sequences– Synonyms– Indexes– Procedures– Functions– Packages– Triggers

• Collection of database objects– Tables– Views– Sequences– Synonyms– Indexes– Procedures– Functions– Packages– Triggers

Data BlocksData Blocks

• The smallest unit of Input/Output used by Oracle database.

• The size of data block for any database is fixed at the time of creation of the database;

• Some values of the data block size are 2KB, 8KB, 16KB, and 32KB.

• Oracle recommends a size of 8KB

• The smallest unit of Input/Output used by Oracle database.

• The size of data block for any database is fixed at the time of creation of the database;

• Some values of the data block size are 2KB, 8KB, 16KB, and 32KB.

• Oracle recommends a size of 8KB

ExtentsExtents

• The next level of data storage.• One extent consists of a specific number of

data blocks• One or more extents in turn make up a

segment.• When the existing space in a segment is

completely used, Oracle allocates a new extent for the segment.

• The next level of data storage.• One extent consists of a specific number of

data blocks• One or more extents in turn make up a

segment.• When the existing space in a segment is

completely used, Oracle allocates a new extent for the segment.

SegmentSegment

• A segment consists of a set of extents• Each table’s data is stored in its own single

segment.• Each index’s data is stored in a single segment. • More extents are automatically allocated by

Oracle to a segment if its existing extents become full.

• The different types of segments are the data segments, index segments,rollback segments, and temporary segments.

• A segment consists of a set of extents• Each table’s data is stored in its own single

segment.• Each index’s data is stored in a single segment. • More extents are automatically allocated by

Oracle to a segment if its existing extents become full.

• The different types of segments are the data segments, index segments,rollback segments, and temporary segments.

Physical Database StructurePhysical Database Structure

• Password file - which contain the password information for all users.

• Parameter file - which contains all the important information necessary to start a database.

• Datafiles - which contain the application data being stored, as well as any data necessary to store user-IDs, passwords, and privileges.

• Redo log files - which store all the transactions made to the database. These files are also called transaction log files.

• Control files - which store information specifying the structure of the database,such as the name and time of creation of the database and the name and location of the datafiles.

• Password file - which contain the password information for all users.

• Parameter file - which contains all the important information necessary to start a database.

• Datafiles - which contain the application data being stored, as well as any data necessary to store user-IDs, passwords, and privileges.

• Redo log files - which store all the transactions made to the database. These files are also called transaction log files.

• Control files - which store information specifying the structure of the database,such as the name and time of creation of the database and the name and location of the datafiles.

The Physical files that make up a database

Control files

Data filesRedo LogFiles

IdentifyIdentify

Record changes to

Control FilesControl Files

• Contain a list of all other files in the database

• Key information such as– Name of the database– Date created– Current state– Backups performed– Time period covered by redo files

• Contain a list of all other files in the database

• Key information such as– Name of the database– Date created– Current state– Backups performed– Time period covered by redo files

• Store a recording of changes made to the database as a result of transactions and internal Oracle Activities

• When Oracle fills one redo log, it automatically fills a second.

• Used for database recovery

• Store a recording of changes made to the database as a result of transactions and internal Oracle Activities

• When Oracle fills one redo log, it automatically fills a second.

• Used for database recovery

Redo Log FilesRedo Log Files

Security MechanismsSecurity Mechanisms

• Database users and schemas

• Privileges

• Roles

• Storage settings and quotas

• Resource limits

• Auditing

• Database users and schemas

• Privileges

• Roles

• Storage settings and quotas

• Resource limits

• Auditing

Data Access: SQLData Access: SQL

• Data definition language (DDL) statements

• Data manipulation language (DML) statements

• Transaction control statements

• Session control statements

• System control statements

• Embedded SQL statements

• Data definition language (DDL) statements

• Data manipulation language (DML) statements

• Transaction control statements

• Session control statements

• System control statements

• Embedded SQL statements

TransactionsTransactions

• A transaction is a logical unit of work that comprises one or more SQL statement executed by a single user. According to the ANSI/ISO SQL standard, with which Oracle is compatible, a transaction begins with the user’s first executable SQL statement. A transaction ends when it is explicitly committed or rolled back.

• A transaction is a logical unit of work that comprises one or more SQL statement executed by a single user. According to the ANSI/ISO SQL standard, with which Oracle is compatible, a transaction begins with the user’s first executable SQL statement. A transaction ends when it is explicitly committed or rolled back.

Transaction ExampleTransaction Example